Method and apparatus for clamping the trunk of a Christmas tree

ABSTRACT

The invention relates to a method and an apparatus for clamping the trunk of a Christmas tree or the like, consisting of a stand, with at least three clamping jaws (5), which are disposed in a base plate (1) with an opening (2) for accommodating the trunk, are distributed about this opening (2) and can be moved into the accommodating opening (2) for clamping the trunk. 
     In order to be able to adapt the clamping jaws easily to the cross section of the trunk, to clamp the trunk securely with a small lift and to undo or eliminate the clamping easily, a fastener, which can be moved in two opposite directions and, in one direction moves the clamping jaws (5) out of the accommodating opening (2) and, in the other direction, initially releases the clamping jaws (5) so that they can move to lie against the trunk and subsequently presses the clamping jaws (5) with the required clamping force against the trunk, is assigned to the base plate (1).

The invention relates to an apparatus for clamping the trunk of aChristmas tree or the like, consisting of a stand, with at least threeclamping jaws, which are disposed in a base plate with an opening foraccommodating the trunk and are distributed about this opening and canbe moved into the accommodating opening for clamping the trunk.

For setting up Christmas trees, apparatuses are known, which are calledstands and consist of a housing-like or frame-like supporting body,which has an accommodating opening, into which the lower region of thetrunk of the Christmas tree can be inserted. Since the cross section ofthe trunks of Christmas trees differs and the Christmas trees must bealigned with their trunk in a vertical position, the opening of thesupporting body is always larger than the maximum cross section of thetrunk. Different apparatuses have become known for securing or clampingthe trunk in this accommodating opening.

The German Offenlegungsschrift 36 06 778 discloses a Christmas treestand, for which roll-shaped holding elements are pressed by arotational movement against the trunk. It is not possible to fit thisholding element individually to the shape of the trunk. Since the trunksof Christmas trees rarely are straight and uniformly round, the trunkcan be aligned only by mechanical processing or connections. In order tobe able to carry out the rotational movement, the Christmas tree standmust be fixed to the floor so that it does not rotate along. No safetymechanism is provided to prevent an automatic opening.

The German Auslegeschrift 28 14 830 discloses a stand, which is alsosuitable for accommodating Christmas trees. In the case of this stand,the holding force is applied exclusively by a strong spring. The openingis accomplished by way of a lever at the bottom of the sleeveaccommodating the trunk. As a result, the simultaneous use of the sleeveas a water container is precluded.

In the German utility patent 94 18 483, a Christmas tree stand isdescribed and shown, for which several holding elements are movedagainst the trunk by means of a rod with a denticulation and a leverwith locking mechanism engaging thereon are moved against the trunk. Inthe case of trunks with relatively small cross sections, several liftingmotions of the lever are required, until the clamping position isreached.

Finally, the German Offenlegungsschrift 39 32 473 discloses a Christmastree stand, for which several holding elements are brought up to thetrunk by shortening a rope loop. At the same time, the holding forcebecomes active only when all holding elements lie against the trunk. Therope is put under tension by a foot lever, so that, in every case,several lifts are required before all holding elements lie against thetrunk. The rope, functioning as the actual clamping element, is fixed inits holding position by a latch mechanism. An additional lever isrequired for loosening the rope. The rope, serving as clamping element,cannot transfer any forces when the holding elements are opened. Forthis reason, for the reverse motion of the holding elements, specialsprings are provided, the force of which must be dimensioned so thatthey can pull out holding elements, which may have penetrated into thetrunk, and can also overcome the friction of the rope.

It is therefore an object of the invention to indicate a method forclamping the trunk of a Christmas tree or the like, by which method itbecomes possible to adapt the clamping jaws easily to the cross sectionof the trunk and to clamp the trunk securely and which does not requirea large lift for the actual clamping motion. Moreover, it shall be aneasy matter to loosen or cancel the clamping.

Pursuant to the invention, it is proposed for accomplishing thisobjective for a method of the type described above that the clampingjaws are moved by way of the fastener against the force of elasticelements out of the accommodating opening, that, after the trunk isinserted, the clamping jaws are released by a movement of the fastenerand, at first, are brought into contact with the trunk by slightlytensioned elastic elements and that only subsequently the clamping jawsfirmly clamp the trunk by means of a further movement of the fastener.

By means of such a method, the clamping jaws are brought into contactwith the trunk for a clamping movement initially by the force of theelastic elements. Only then is the actual clamping motion initiated byway of the fastener. The lift required for this is relatively slight.The path of the fastener for loosening the clamping and, with that, forreleasing the accommodating opening, is also relatively short. Even atrunk, clamped particularly firmly, can be loosened easily and reliably.

Further distinguishing features of an inventive method and apparatus aredisclosed in the claims.

The invention is described in greater detail in the following by meansof an example, which is shown in a simplified manner in the drawing, inwhich

FIG. 1 shows a plan view of an inventive apparatus in the loosenedposition,

FIG. 2 shows the apparatus of FIG. 1 in the clamped position,

FIG. 3 shows the arrangement of the apparatus of FIGS. 1 and 2 in astand and

FIG. 4 shows a plan view of the configuration of an actuator.

In FIGS. 1 to 4 of the drawing, an apparatus for clamping the trunk of aChristmas tree, which is only indicated, is shown. To begin with, theapparatus consists of a base plate 1 with a circular outer contour. Anaccommodating opening 2, which also has a circular cross section, isincorporated in this base plate 1. The base plate 1 is disposed on apot-like vessel 4 (FIG. 3), the bottom of which is provided with acentering point 3 and which can be used for accommodating water.

In the example shown, three bolts 6 are disposed on the base plate 1.They extend perpendicularly to the surface of the base plate 1 and eachpivotably accommodates a clamping jaw 5. At each clamping jaw 5, one endof a spring 7 is connected, the other end of which is secured to thebase plate 1. In the example shown, the springs 7 engage the clampingjaws 5 in such a manner, that the latter endeavor to turncounterclockwise on the bolts 6. This means that the clamping jaws 5time and again attempt to assume a position as far as possible withinthe accommodating opening 2, as can be seen in FIG. 2.

At their ends protruding into the accommodating opening 2, the clampingjaws 5 are provided with a corrugation or denticulation which, oversprings 7, can be brought to lie against the trunk, which is onlyindicated. At their other end, the clamping jaws 5 have a circularlyextending denticulation 11.

A fastening ring 9, on which, in the example shown, there are a total ofthree dogs 8 and three catches 10, is assigned to the base plate 1. Ofthese, in each case one dog 8 and one catch 10 are assigned to aclamping jaw 5. The dogs 8 in each case serve for moving the clampingjaws 5 open, whereas the catches 10 are responsible for the movement, bymeans of which they are clamped fast By means of an appropriaterotational movement of the fastening ring 9, either the dogs 8 or thecatches 10 come to lie or act against a clamping jaw 5. According to therepresentation of FIG. 1, the fastening ring 9 was turned in theclockwise direction, so that now a dog, which has moved the clampingjaws 5 into their open position, lies against all three clamping jaws 5.As soon as the trunk, which is indicated in FIGS. 2 and 3, was insertedinto accommodating opening 2, the fastening ring 9 is rotatedcounterclockwise. With that, the dogs 8, which lie against the clampingjaws 5 in FIG. 1, are removed and the clamping jaws 5 can be swiveled bytheir springs 7 in such a manner, that they lie with their corrugationor denticulation against the trunk (FIG. 2), Upon furthercounterclockwise rotation of the fastening ring 9, the catches 10 engagethe denticulation 11 of the clamping jaws 5, which leads to a clampingof the inserted trunk.

An actuator 12 to 15 is assigned to the fastening ring 9 for moving it.This actuator 12 to 15 consists first of all of a bolt 15, which isdisposed at the underside of the fastening ring 9. This bolt 15 engagesa spirally extending guiding slot 14 of a drum 13, which is mounted in afixed position and can be turned by a lever 12. By appropriatelyswiveling the lever 12, the drum 13 and, with that, at the same timealso the fastening ring 9 can be rotated in the appropriate direction,When the lever 12 is swiveled downward out of the position shown in FIG.3, the drum 13, and with that the fastening ring 9 are turned in such amanner, that the clamping jaws 5 clamp the indicated trunk. However, ifthis lever 12 is raised, the clamping jaws 5 return to their initialposition of FIG. 1. If necessary, the lever 12 can be inserted looselyinto the drum 12, so that it can be removed as a safeguard against theunintentional loosening of the clamping. According to the representationin FIG. 3, the apparatus described, together with the vessel 4 and theactuator 12 to 15, is accommodated in a housing 16, which has a slot 17,through which the lever 12 passes to the outside.

In a modification of the example described, it is possible to swivel theclamping jaws 5 by friction. Moreover, the fastening ring 9 is formedfrom two rings which, between them, enclose the corresponding end of theclamping jaws 5. If necessary, the interacting engaging surfaces of theclamping jaws 5 and of the fastening ring 9 are provided with a coatingto increase the friction. Moreover, it is possible to dispose theclamping jaws 5 so that they can be set radially on the base plate 1.The described actuator for moving the clamping jaws 5 can also beconstructed in a different manner.

I claim:
 1. An apparatus for clamping a trunk of a tree, comprising:astand including a base plate with an opening for accommodating thetrunk; at least three clamping jaws which are disposed on the baseplate, the at least three clamping jaws being distributed about theaccommodating opening and being movable to a position for clamping thetrunk within the accommodating opening; and a fastener which can bemoved in a first direction for moving the clamping jaws out of theaccommodating opening and, in a second direction for pressing theclamping jaws against the trunk with a required clamping force, thefastener including dogs and catches for effecting movements of theclamping jaws, the dogs and the catches interacting with the clampingjaws only in specified positions, the clamping jaws each having adenticulation for a corresponding one of the catches, and the clampingjaws being biased in a direction inward of the accommodating opening andinto contact with the trunk.
 2. The apparatus of claim 1, wherein theclamping jaws are disposed on the base plate such that they are eachpivotable about an axle.
 3. The apparatus of claim 1, wherein theclamping jaws are disposed radially displaceably on the base plate. 4.The apparatus of claim 1, 2 or 3, wherein the elastic elements includeone of a spring and a strip of elastic.
 5. The apparatus of claim 1, 2or 3, further comprising an actuator assigned to the fastener.
 6. Theapparatus of claim 1, 2 or 3, wherein the fastener includes a rotatablefastener ring.
 7. An apparatus for clamping a trunk, comprising:a standincluding a base plate having an accommodating opening for reception ofthe trunk therethrough; at least three clamping jaws mounted on the baseplate and spaced apart peripherally about the accommodating opening,said at least three clamping jaws being movable from a first positionpermitting slidable reception of the trunk therebetween, to anotherposition in which said at least three clamping jaws contact the trunkfor clamping thereof within the accommodating opening, said at leastthree clamping jaws being biased inwardly of said accommodating opening;and a fastener movable in a first direction and in a second directionopposite said first direction, said fastener including dogs and catchesfor effecting movement of the clamping jaws between said first andsecond positions responsive to movement of said fastener in said firstand second directions, respectively, the dogs and the catchesinteracting with the clamping jaws only in specified positions, theclamping jaws each including structure for engaging a corresponding oneof the catches, movement of said fastener in said first directioneffecting movement of the clamping jaws outward of the accommodatingopening by engagement of said dogs with said clamping jaws and, movementof said fastener in said second direction operating to urge the clampingjaws against the trunk, continued movement thereof in said seconddirection urging said clamping jaws against the trunk with a desiredclamping force.
 8. The apparatus according to claim 7, wherein theclamping jaws are each pivotably mounted on the base plate.
 9. Theapparatus according to claim 7, wherein the clamping jaws are disposedradially displaceably on the base plate.
 10. The apparatus according toclaim 7, wherein said at least three clamping jaws are biased inwardlyof said accommodating opening by one of a spring and a strip of elastic.11. The apparatus according to claim 7, further comprising an actuatorfor rotating the fastener in response to force applied thereto.
 12. Theapparatus according to claim 7, wherein the fastener includes arotatable fastener ring.
 13. The apparatus according to claim 7, furthercomprising an open-top vessel for accommodating water, said base platebeing disposed on said vessel.
 14. A method for clamping a trunk of atree into an accommodating opening of a stand by means of clamping jawswhich can be moved in the accommodating opening by operation of afastener in two opposite directions, the method comprising:applying abiasing force to the clamping jaws for urging same in a direction inwardof the accommodating opening; moving the clamping jaws against thebiasing force out of the accommodating opening by movement of thefastener in a first direction; inserting the trunk in the accommodatingopening; releasing the clamping jaws by movement of the fastener in asecond direction to bring the clamping jaws into contact with the trunkby operation of the biasing force; and firmly engaging the clamping jawsagainst the trunk by further movement of the fastener in said seconddirection, whereby the clamping jaws clamp the trunk therebetween. 15.The method of claim 14, wherein the movement of the fastener in saidfirst direction and said second direction is transferred respectively bydogs and catches to the clamping jaws.
 16. The method of claim 14,wherein the movement of the fastener in said first direction and saidsecond direction is transferred to the clamping jaws by friction. 17.The method of claim 14, 15 or 16, wherein said step of applying abiasing force includes providing a pretensioned elastic element, theclamping jaws being brought into contact with the trunk in said step ofreleasing by operation of the pre-tensioned elastic element.